Separating apparatus



Dec. 3, 1963 R. P. MOORE 3,113,100

SEPARATING APPARATUS Filed March 2, 1959 2 Sheets-Sheet 1 Dec. 3, 1963 R. P. MOORE SEPARATING APPARATUS cs-Sheet 2 Filed March 2, 1959 M m N 33 A Q m U United States Patent 3,113,100 SERARATENG APPARATUS Richard P. Moore, Argosy House, Spiishury St, Germiston, Republic of South Africa Filed Mar. 2, 1959, 58!. No. 796,582 Claims priority, application Republic of South Africa Mar. 8, 1958 Claims. (Cl. 210-91) This invention relates to separating tanks of the kind adapted for treatment of sewage, mud, pulps of many kinds and some forms of industrial waste. The invention also relates to tanks for use in the purification or treatment of water. The invention has particular reference to tanks of the particle or slurry-contact type in which a slurry or particle mass is created and maintained in suspension to assist in the solids liquid separation and treatment of the incoming liquid.

The kind of separating unit to which the invention refers exclusively is that including a tank into which the material or liquid to be treated is delivered and a number of arms arranged to sweep over the tank floor for the purpose of motivating sludge or heavy settled fractions towards a draw-off point, clearing the tank floor or merely for maintaining a slurry suspended above the floor. Tanks of this nature are well known but in all separating units within the knowledge of the inventor the arms are always driven through an electrical or mechanical drive of some sort, the driver being located outside the tank. In some cases the driving unit, for example an electric motor, is located on a bridge above the tank, a drive shaft projecting upwardly from the member on which the arms are nested.

In other arrangements the motor is located a well below the tank with the drive shaft projecting through the the tank base.

A big drawback of the units described above is the expense involved in providing the driving unit. In addition, of course, there are the additional constructional requirements where a bridge over the tank has to be provided.

An object of the present invention is to provide a separating unit which has advantages over the units presently in use.

According to the present invention as separating unit of the kind referred to includes one or more nozzles mounted on the arm or arms an dada-pted to the directed away from the intended direction of rotation of the arm or arms; and means to propel pressure fluid through the or each nozzle to form a driving jet or jets to rotate the arm or arms.

Further according to the invention the unit includes one or more additional nozzles placed along t e arm or arms and adapted to expel jets of pressure fluid, the additional nozzle or nozzles being located to urge settled fractions towards a discharge point in the tank.

Also according to the invention the arms are mounted for rotation about a central pivot point at a low level in the tank and fluid for the jets is fed along the arms from the pivot point.

In the preferred arrangement the arms are nested around a cap adapted to fit as a sleeve over an upstanding hollow post, the cap and post providing engaging bearing surfaces and the arrangement being such that pressure fluid is fed through the post and into the arms.

To ease the load on the upstanding post buoyancy means may be employed to counter-balance the weight of the arms. Bafi'ie means may be provided to direct incoming material to the tank along the floor thereof; in this respect the base of the buoyancy means could be adapted to provide the necessary batlle.

Further, to control the speed of rotation of the arms 3,1 13,1 6% Patented Dec. 3, 1963 vanes may be used, the vanes being coupled to the arms and their inclination being variable. These vanes are preferable of dimensions sufficient also to control the current flow set up in the tank due to movement of the arms.

The invention also provides for driving jet nozzles rotatable on the arms so that their inclination to the tank iloor may be varied. Further the driving jets are preferably located far out on the arms and are directed for the jets therefrom to impinge against the walls of the tank. \For certain applications it may be wise to incorporate nozzles for the additional jets which are also rotatable on the arms so that their inclination to the tank floor may be varied.

The invention envisages a unit in which material to be treated is fed into the tank to about mid-point of the floor thereof and the additional nozzles are directed to disperse the material outwardly towards the tank walls. However, it will be appreciated that the invention is in no way con-fined to such an arrangement. Circumstances may arise in which the material is fed in at the top or sides of the tank.

Draw-oh of heavy settled fractions may take place at any convenient point in the tank. In some cases the draw-off will be at the centre of the tank floor but in the embodiment to be described hereunder the draw-off is positioned at the boundary of the floor and side walls of the tank.

According also to the invention means is provided to feed supernatant liquid overflowing at the top of the tank through the nozzles to provide the jet or jets.

To illustrate the invention an embodiment is described hereunder with reference to the accompanying drawings in which FIGURE 1 is a plan view of a unit in accordance with the invention with parts broken away;

FIGURE 2 is a section on the line 2-2 of FIGURE 1;

FIGURE 3 is a sectional side elevation with parts broken away; and FIGURE 4 is a sectional plan of a driving nozzle arrangement.

Referring to FIGURE 1, the separation unit includes a cylindrical tank 5, four symmetrically arranged arms 6 nested about a central pivot and adapted to sweep across the floor 7 of the tank, a pump 8 for pumping supernatant liquid overflowing the tank through driving nozzles 9 located far out on the arms and a sump 10 through which heavy settled fractions are removed from the tank by means of pump 11.

The liquid being forced through the nozzles 9 emerges in the form of jets and these jets are utilised to propel the arms across the floor of the tank.

In FIGURE 3 further nozzles 12 are shown and these additional nozzles are used purely for the purpose of directing settled heavy fractions towards the sludge drawoff point constituted by the sump It). In other embodiments it may be necessary to call upon the additional jets to aid in propelling the arms and in these cases the nozzles will have to be inclined rearwardly to ensure that the jets have a sufficient driving component.

In the embodiment the phrase material to be treated will be understood as including all sewage, muds, pulps and water requiring treatment such as purification, sedimentation or softening. The material to be treated is urged into the tank through the duct 14 leading to a central discharging point 15 in the tank floor. By baffle means, to be described later, the material is directed outwardly towards the tank walls 16 at low level. On striking the walls the material is given an upward lift and returns towards the centre of the tank on coming into contact with the ring-like deflecting bailie 17 situated about midway up the walls.

It will be appreciated that the provision of ballies such pending skirt 28.

as 17 is an optional matter and in any case depends upon the requirements of any given case. Sometimes no bailies at all will be required.

As the heavy fractions in the material settle out so the additional jets sweep the tank floor and urge them towards the boundary of the tank floor and walls 16. Further, the driving jets are so located that they in turn force the slurry in the region of the boundary referred to towards the sump It). In addition they are arranged to sweep the lower part of the walls clear of any heavy material adhering thereto. In the drawings only one sump has been shown but circumstances may warrant the use of several such draw-off points. The sump is cleared by means of the pump 11.

In the upper half of the tank a series of vertical baffles 19 are provided to maintain the upper zone as quiescent as possible. Supernatant liquid flows over the top of the tank into a launder 2t) and portion of the overflow is used to provide the necessary driving and additional jets. Pipe line 21 leads the portion of the overflow referred to in the previous sentence to the pump 8 which directs it along the line 22 into an upstanding support post 23. It will be appreciated that control of the speed of the arms and control of the degree of suspension of the slurry in the tank may be accomplished by varying the feed of liquid to the nozzles.

The post 23 provides a bearing surface at its top for a sleeve 24 which fits over the post rather like a cap. The cap and post are suitably packed to prevent leakage in either direction and the liquid entering the post passes out through perforations 26 in the post. As shown the arms are nested on the sleeve and the arms are in the form of hollow tubes; liquid flowing along the arms from the sleeves.

To minimize the forces acting downwardly on the post, buoyancy means 27 is provided. This means takes the form of a conically shaped air filled vessel with a de- Slots 29 in the skirt allow for the location of the arms and the skirt itself ensures that material entering the tank is not allowed to how vertically to disturb the liquid in the quiescent zone. As shown in FIG- URE 3 the material is forced to follow the path shown by arrows 30.

In the embodiment fixed nozzles are used but circum stances may arise in which the angle of inclination of the nozzles might require alteration. They may therefore be rotatably mounted on the arms.

In FIGURES 1 and 4 the arrow 31 indicates the direc tion of movement of the arms while the arrows 32 in FIGURE 4 indicate the flow of pressure liquid through a driving nozzle 9.

An additional feature is the use of vanes 33 to control the speed of the arms across the tank floor. These vanes are located on the arms and may be rotated thereon into any desired position. With the type of vane shown in the figures useful control is obtained over the currents set up in the lower half of the tank. By inclining them in the direction of travel the heavy fractions will a be urged to pass under the arms as they sweep across the Stay wires 35 give added support to the arms and relieve the strain on the sleeve 24. In the preferred embodiment a mast 36 is provided for the purpose of indicating the behaviour of the arms, the mast terminating in a suitable tell-tale means 37 projecting above the level of liquid in the tank.

Many embodiments of the invention exist each differing from the other in detail but in no way departing from the principle of the invention.

The number of driving jets will depend upon the type of operation for which the tank is required. Obviously heavy slurries will require more driving jets than in the case of light slurries for the same nozzle pressures. In the figures the arms are shown as having five driving nozzles each. The jets formed by these nozzles impact A} against the heavy slurry in the lower half of the tank and against the tank walls and the resultant reaction forces the arms around the floor in the. direction of the arrow 31.

I claim:

1. A separating unit comprising a tank having a floor and side wall means, an inlet for liquid to be treated, said inlet terminating at said fioor, an outlet for treated liquid near the top of said tank, a hub, a plurality of hollow arms each having one end mounted on said hub and being rotatable in said tank adjacent to said floor, a supply pipe for liquid under pressure, means located in said tank and connected with said supply pipe for rotatably supporting said hub and for establishing communication between said supply pipe and said arms, a sludge pocket in said floor, said arms having sections passing over said sludge pocket during rotation of said arms, an annular portion of said floor vertically below said sections and including said sludge pocket, nozzles mounted on said sections and directed laterally from said arms to discharge jets directed along said annular portion and by their reaction impart rotation to said arms, and other nozzles on said arms directed downwardly from said arms and radially outward from the center of said tank toward said annular portion to induce a radial flow toward said annular portion during rotation of said arms.

2. The separating unit of claim 1 in which the floor of said tank is circular and said side wall means cylindrical, said sludge pocket and said annular portion being located adjacent to said side wall means.

3. The combination of claim 1, some of the nozzles on each or" said arms being spaced on different distances from said hub than the nozzles on other of said arms.

4. A separating unit comprising a tank having a floor and side wall means, inlet means for liquid to be treated, said inlet means terminating at the central portion of said floor, outlet means for withdrawing treated liquid near the top of said tank, a plurality of hollow arms rotatable in said tank adjacent to said floor, a supply pipe for liquid under pressure, means centrally located in said tank and connected with said supply pipe for rotatably supporting said arms and for establishing communication between said supply pipe and said arms, rotatable batlie means adjacent to said floor, connected with said arms and facing said inlet means to divert the direction of flow of liquid entering through said inlet means and to cause in said tank immediately adjacent to said floor a horizontal flow directed from said inlet means toward said side wall means, and a plurality of nozzles mounted on and connected with said hollow arms, certain of said nozzles being directed laterally from said arms to impart rotation to said arms and others of said nozzles being directed downwardly from said arms and outwardly from the center of said tank to aid said horizontal flow.

5. In the combination of claim 4, a pump having an inlet and an outlet, said inlet being connected with said outlet means, and said outlet being connected with said supply pipe.

6. A separating unit comprising a tank having a floor and side wall means, an inlet for liquid to be treated, said inlet terminating at the central portion of said floor, an outlet for treated liquid near the top of said tank, a hub, a plurality of hollow arms mounted on said hub and rotatable in said tank adjacent to said floor, a supply pipe for liquid under pressure, support means located in said tank and connected with said supply pipe for rotatably supporting said hub and for establishing communication between said supply pipe and said arms, bafile means adjacent to said floor, and facing said inlet to divert the direction of flow of liquid entering through said inlet and to cause in said tank immediately adjacent to said floor a horizontal flow directed from said inlet toward said side wall means, a plurality of nozzles mounted on and connected with said hollow arms, certain of said nozzles being directed laterally from said arms to impart rotation to said arms and others of said nozzles being directed downwardly from said arms and outwardly from the center of said tank to aid said horizontal flow, and a mast extending inwardly from said side wall means toward the center of said tank and upwardly from said hub, a telltale mounted on the upper part of said mast, and stays extending from said mast to the outer ends of said arms.

7. A separating unit comprising a tank having a floor and side wall means, an inlet for liquid to be treated, said inlet terminating at the central portion of said floor, an outlet for treated liquid near the top of said tank, a plurality of hollow arms rotatable in said tank adjacent to said floor, a supply pipe for liquid under pressure, means centrally located in said tank and connected with said supply pipe for rotatably supporting said arms and for establishing communication between said supply pipe and said arms, ba'tlle means facing said inlet to cause in said tank immediately adjacent to said floor a horizontal flow radially away from said inlet, a plurality of nozzles mounted on and connected with said hollow arms, certain of said nozzles being directed laterally from said arms to impart rotation to said arms and others of said nozzles being directed downwardly from said arms and outwardly from the center of said tank to aid said horizontal flow, and an annular baffie extending parallel to said floor and horizontally along the lower portion of said side wall means at an elevation above said arms and below the top of said tank to reverse the direction of said horizontal flow.

8. A separating unit comprising a tank having a floor and side wall means, an inlet for liquid to be treated, said inlet terminating at the central portion of said floor, an outlet for treated liquid near the top of said tank, a plurality of hollow arms rotatable in said tank adjacent to said floor, a supply pipe for liquid under pressure, means centrally located in said tank and connected with said supply pipe for rotatably supporting said arms and for establishing communication between said supply pipe and said arms, baffle means facing said inlet to cause in said tank adjacent to said floor a horizontal flow away from said inlet, a plurality of nozzles mounted on and connected with said hollow arms, certain of said nozzles being directed laterally from said arms to impart rotation to said arms and others of said nozzles 6 being directed downwardly from said arms and outwardly from the center of said tank to aid said horizontal flow, and vertical batlles mounted on said side wall means and extending inwardly from said side wall means toward the center of said tank and upwardly in said tank from a level above said arms.

9. The separating unit of claim 7, said annular baffie having a horizontal lower face extending from said side wall means towards the vertical center line of said tank and an inclined upper face sloping from said side wall means downwardly towards the vertical center line of said tank.

10. A separating unit comprising a tank having a fioor and side wall means, an inlet for liquid to be treated located at said floor, a sludge pocket in said floor remote from said inlet, deflector means located at a low level in said tank and facing said inlet to deflect the direction of flow of said incoming liquid to create a radially outward flow along said floor in a horizontal stratum, a peripheral bafile on the lower portion of said side wall means extending parallel to said door to re-deflect said radially outward flow towards the vertical. center line of said tank in a horizontal stratum above said first named horizontal stratum, a plurality of hollow arms rotatable in a plane adjacent and parallel to said floor and connected to a supply of pressure fluid, nozzles mounted at the extremities of said arms and directed laterally from said arms for causing rotation of the arms as the result of the reaction of the pressure fluid expelled therefrom, other nozzles on said arms directed downwardly from said arms and outwardly from the center of said tank to direct jets of pressure fluid over said floor to assist said radially outward flow and to motivate settled sludge to said sludge pocket, and an outlet for treated liquid near the top of said tank.

References Cited in the file of this patent UNITED STATES PATENTS 1,152,769 Trent Sept. 7, 1915 2,036,809 Humphreys et al. Apr. 7, 193 2,267,608 Hawley Dec. 23, 1941 2,649,412 Kivari et al. Aug. 18, 1953 2,678,912 Kalinski et a1 May 18, 1954 2,816,661 Bounin Dec. 17, 1957 2,899,071 Bounin Aug. 11, 1959 

6. A SEPARATING UNIT COMPRISING A TANK HAVING A FLOOR AND SIDE WALL MEANS, AN INLET FOR LIQUID TO BE TREATED, SAID INLET TERMINATING AT THE CENTRAL PORTION OF SAID FLOOR, AN OUTER FOR TREATED LIQUID NEAR THE TOP OF SAID TANK, A HUB, A PLURALITY OF HOLLOW ARMS MOUNTED ON SAID HUB AND ROTATABLE IN SAID TANK ADJACENT TO SAID FLOOR, A SUPPLY PIPE FOR LIQUID UNDER PRESSURE, SUPPORT MEANS LOCATED IN SAID TANK AND CONNECTED WITH SAID SUPPLY PIPE FOR ROTATABLY SUPPORTING SAID HUB AND FOR ESTABLISHING COMMUNICATION BETWEEN SAID SUPPLY PIPE AND SAID ARMS, BAFFLE MEANS ADJACENT TO SAID FLOOR, AND FACING SAID INLET TO DIVERT THE DIRETION OF FLOW OF LIQUID ENTERING THROUGH SAID INLET AND TO CAUSE IN SAID TANK IMMEDIATELY ADJACENT TO SAID FLOOR A HORIZONTAL FLOW DIRECTED FROM SAID INLET TOWARD SAID SIDE WALL MEANS, A PLURALITY OF NOZZLES MOUNTED ON AND CONNECTED WITH SAID HOLLOW ARMS, CERTAIN OF SAID NOZZLES BEING DIRECTED LATERALLY FROM SAID ARMS TO IMPART ROTATION TO SAID ARMS AND OTHERS OF SAID NOZZLES BEING DIRECTED DOWNWARDLY FROM SAID ARMS AND OUTWARDLY FROM THE CENTER OF SAID TANK TO AID SAID HORIZONTAL FLOW, AND A MAST EXTENDING INWARDLY FROM SAID SIDE WALL MEANS TOWARD THE CENTER OF SAID TANK AND UPWARDLY FROM SAID HUB, A TELLTALE MOUNTED ON THE UPPER PART OF SAID MAST, AND STAYS EXTENDING FROM SAID MAST TO THE OUTER ENDS OF SAID ARMS. 